Coated fabric and method of preparing same



, Patented Nov. 24, 1931 UNITED STATES PATENT OFFICE ARTHUR H. BARRETT,OF WILMINGTON, DELAWARE, A SSIGNOE TO E. I. DU IONT DE NEMOURS 86COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION OI DELA- WARE- NoDrawing.

The invention relates to a fabric coating composition and a method ofpreparing the same, and more particularly to a fabric coatingcomposition utilized in the production of artificial leathers suitable.for automobile tops, automobile trimmings, upholstery, lugin cost andvery liable to cold crack. T e

rubberized fabrics have been found to be poor bases for the varnish topcoat with which it is customary to finish automobile tops. This isprobably due to the difference in the elasticity of the rubber and thevarnish. Pyroxylin coated fabrics have the drawback of requiring anumber of coatings to give the required thickness, each coat having tobe dried separately. Bituminous coated fabrics containing more thansmall amounts of the bituminous material have heretofore been avoidedbecause such compositions were found to give a stiff, brittle productsubject to cold cracking.

An object of the present invention is to provide a fabric coatingcomposition, which contains a large percentage of bituminous material,and which is free from the objections of the prior art.

Another object of the invention is. to pro-- duce an artificial leatherwhich is flexible and has a calendered surface capable of serving as asatisfactory base for the varnish top coat.

These objects are attained by my invention,

which produces an artificial leather suitable for the purposes named, byapplying to a flexible fabric backing a calender coating compositioncontaining bituminous. material as its principal ingredient, and bakingthe coated fabric at a temperature above 100 C.

COATED FABRIC AND METHOD OF PREPARING am Application filed September 9,1927. Serial No. 218,577.

and below the decomposition point of the ingredients In some instances afurther step is introduced, which consists in applying a top varnishcoat to the calender coat befor baking. An important feature of theprese r lt invention isthe novel composition of the calender coat, whichcontains, in addition to the bituminous material, various modifyingagents which 'will be more fully described and specified hereinafter.

' In carrying out the present invention, the materials making up thebituminous calender coat are mixed or combined in a rubber mill ormixing machine in a similar manner to that ordinarily used in mixingrubber compositions. After mixing, the composition is calendered out onthe particular base to be used. Subsequently, the calender coatedmaterial may be embossed, if desired, and thereafter varnished, afterwhich it is baked at a temperature suflicient to soften and season thebituminous material and to bring about vulcanization in those caseswherein the composition contains vulcanizable products. For the bakingoperation the goods are ordinarily fes'tooned in a chamber pro- I videdwith heat such as a vulcanizing chamber.

More in detail, the present invention contemplates forming the calendercoat principally of one or more bituminous materials such as stearinpitch, asphalt, petroleum flux and the like, the bituminous content ofthe calender coat ranging from thirty to eighty per cent of thecomposition. In order to modify the properties of the bituminousmaterial, various agents, such as an indurator, a softener and a fillermay be employed.

The purpose of the indurating agent is to harden and toughen thecomposit1on. For this action, organic vulcanized materials, such asvulcanized rubber, or a vulcanized oil, for instance factis, may beused. Vulcanizable products, such as rubber, vegetable oil, drying oil,together with a vulcanizing agent, for example, sulfur or sulfur with anaccelerator may be employed. These indurating agents may be usedseparately or in combination and they are normally used in a proportionnot exceeding the bituminous material etc. The proportion of of thecomposition. In fact,-it is preferable to use the indurating agents in aproportion between 10 and 100 parts of indurating agent per 100 parts ofbituminous material.

For softening agents, I use, in general, that class of compoundsordinarily utilized for the purpose in rubber compounds, namely,petroleum, mineral oil, vegetable oil, rosin oil,

of bituminous material. v

Fillers are added to the composition for the purpose of toughening thecalender coat K and reducing the cost. Finely divided solid materialswhich are stable at the temperature of operation, such as whiting,lithopone, lime flour, litharge, iron oxide, carbon black, etc., aresuitable for this use. However, vided fibrous materials, for example,asbestos, cotton linters, wood pulp and the like, may be used, thefiller being used in a proportion between 15 to'150 parts per 100 partsof bituminous material. 1

An oil varnish or an asphalt varnish, or a varnish containing bothdrying oil and asphalt, may be used as a varnish coat. It isparticularly advantageous to use an asphalt which softens at the bakingtemperature. In some cases one coat of drying oil varnish and a top coatof asphalt varnish may be used. However, the present invention isnotlimited ;to a product having a varnish coat, and it has been found thata superior product may be produced merely by calendering a. bituminouscomposition such as has been described, on .to

a suitable backing, and finishing by baking at a vulcanizingtemperature.

The backing or base fabric may be any suitable material having thenecessary strength and flexibility,- for instance, felt, cloth or paper.

The following is one example of the method of manufacturing artificialleather according to the present invention:

Two fabrics are combined with an adhesive rubber cement and upon thesurface of this double fabric the following composition is calendered toa suitable thickness:

Bituminous composition N0. 1

Parts Bituminous material Stearin pitch 45 Blown petroleum flux 5Indurating agent Reclaimed rubber 30 Sulfur 0.5 Softening agent Mineraloil 0.5 Filler h 10 Litharge 5 Lime flour 4 mg then' festooned in avulcanizing chamber.

The vulcanizing chamber is heated to the proper temperature which, inthis case, is about 123 C. and is maintained at this temsoftening agentused is generally from 3 to 15 parts per 100 parts ,coat of black,drying oil varnish to the calendered embossed material before applyingthe final coat of asphalt varnish. In this case, it is desirable to drythe first coat of varnish before the second is applied. This isaccomplished by festooning the goods after applying the first coat ofvarnish and heating at a temperature and for a length of time sufficientto dr the varnish properly.

The fol owing are examples of variations of the bituminous coatingcomposition which may be used in the above process according to theinvention and which fall within the limits which I have alreadydescribed:

Bituminous composition No. 2

Bituminous material Stearin pitch 0 Blown petroleum flux Induratingagent Smoked sheets A very desirable coating has been prepared by mixingtogether from 10 to 100 parts of the indurating agent, from 3 to 15parts of the softening agent and from 15 to 150 parts of the filler toeach 100 parts-of the bituminousmaterial, the bituminous materialranging from 30 to 80 per cent of the whole composition.

As compared with prior art products intended for similar purposes thecoated fabric of the present invention has the advan tage of low costand long life especially under usage involving exposure to severeconditions of heat, cold, and direct sunlight. In addition, thebituminous calender coat as described has an advantage over knowncompositions for coating artificial leather, in that this calender coatprovides a greatly improved support for any of the varnishes commonlyused for finishing.

laims:

1. A flexible fabric having a calender coat containing an induratingagent, a larger proportion of bituminous material than indurating agent,a softening agent and a filler and a varnish coating thereover.

2. The method of producing a coated fabric which includes the steps ofmixing together an indurating agent, a larger amount Parts of bituminousmaterlal than indurating agent, a softening agent and a filler, coating.

a fabric backing with said mixture, festooning the coated fabric, andheating the said coated fabricto a temperature of above 100" C. butbelow the decomposition point of the said mixture. 7

3. The method of producing a coated fabric which includes the steps ofmixing together an indurating agent, a larger amount of bituminousmaterial than indurating agent, and a softening agent, coating a fabricbacking with said mixture, festooning the coated fabric, and heating thesaid coated fabric'to a temperature of above 100 C. but below thedecomposition point of the said mixture.

4. The method of producing acoated fabric which includes the steps ofmixing together 100 parts bituminous material, 10 to 100 partsindurating agent, 3 to 15 parts softening agent and 15 to 150 partsfiller, applying said mixture to a fabric, festooning the coated fabric,and subjecting the coated fab ric to a temperature sufiicient to bakebut not decompose said mixture.

5. The method of producing a coated fabric which includes the steps offorming a mixture of an indurating agent, a larger amount of bituminousmaterial than indurating agent, a softening agent and a filler, ap-

plying said mixture to a fabric, festooning the coated fabric, andheating said coated fabric to a temperature of above C., but below thedecomposition point of the said mixture, for a period of 2% hours.

In testimony whereof, I aflix my signature.

ARTHUR N. PARRETT.

